Volcanic Winter

"The sun was dark and its darkness lasted for eighteen months; each day it shone for about four hours; and still this light was only a feeble shadow; the fruits did not ripen and the wine tasted like sour grapes." As this Michael the Syrian quote regarding the weather of 536 A.D. demonstrates, a climate catastrophe that blots out the sun can really spoil your day. Procopius of Caesarea remarked: "During this year [536 A.D.] a most dread portent took place. For the sun gave forth its light without brightness. and it seemed exceedingly like the sun in eclipse, for the beams it shed were not clear." Many documents from 535 - 536 A.D.--the time of King Arthur in Britain--speak of the terrible "dry fog" or cloud of dust that obscured the sun, causing widespread crop failures in Europe, and summer frosts, drought, and famine in China. Tree ring studies in Europe confirm several years of very poor growth around that time, and ice cores from Greenland and Antarctica show highly elevated levels of atmospheric sulfuric acid dust existed.

Though some scientists believe the climate calamity of 535-536 A.D. was due to a comet or asteroid hitting the Earth, it is widely thought that the event was probably caused by the most massive volcanic eruption of the past 1500 years. This eruption threw so much sulfur dioxide (SO2) gas into the stratosphere that a "Volcanic Winter" resulted. Sulfur dioxide reacts with water to form sulfuric acid droplets (aerosol particles), which are highly reflective and reduce the amount of incoming sunlight. The potential eruption that led to the 535 - 536 A.D. climate calamity would have likely been a magnitude 7 event on the Volcanic Explosivity Index (VEI)--a "super colossal" eruption that one can expect to occur only once every 1000 years. The Volcanic Explosivity Index is a logarithmic scale like the Richter scale used to rate earthquakes, so a magnitude 7 eruption would eject ten times more material than the two largest eruptions of the past century--the magnitude 6 eruptions of Mt. Pinatubo in the Philippines (1991) and Novarupta in Alaska (1912).

Figure 1. An 18 km-high volcanic plume from one of a series of explosive eruptions of Mount Pinatubo beginning on 12 June 1991, viewed from Clark Air Base (about 20 km east of the volcano). Three days later, the most powerful eruption produced a plume that rose nearly 40 km, penetrating well into the stratosphere. Pinatubo's sulfur emissions cooled the Earth by about 1°F (0.5°C) for 1 - 2 years. (Photograph by David H. Harlow, USGS.)

Super-colossal eruptionsThere has been only one other magnitude 7 "super-colossal" eruption in the past 1500 years--the massive eruption of the Indonesian volcano Tambora in 1815. The sulfur pumped by this eruption into the stratosphere dimmed sunlight so extensively that global temperatures fell by about 2°F (1°C) for 1 - 2 years afterward. This triggered the famed Year Without a Summer in 1816. Killing frosts and snow storms in May and June 1816 in Eastern Canada and New England caused widespread crop failures, and lake and river ice were observed as far south as Pennsylvania in July and August. The Tambora eruption was about 40% smaller than the 535 - 536 A.D. event, as measured by the number of sulfur aerosol particles deposited in Greenland ice cores.

In an article published in 2008 in the American Geophysical Union journal EOS, Dr. Ken Verosub of the University of California, Davis Department of Geology estimated that future eruptions capable of causing "Volcanic Winter" effects severe enough to depress global temperatures by 2°F (1°C) and trigger widespread crop failures for 1 - 2 years afterwards should occur about once every 200 - 300 years. Even a magnitude 6 eruption, such as the 1600 eruption of the Peruvian volcano Huaynaputina, can cause climatic change capable of killing millions of people. The Huaynaputina eruption is blamed for the Russian famine of 1601-1603, which killed over half a million people and led to the overthrow of Tsar Boris Godunov. Thankfully, the climatic impacts of all of these historic magnitude 6 and 7 eruptions have been relatively short-lived. After about two years, the sulfuric acid aerosol particles have settled out of the stratosphere, returning the climate to its former state.

Mega-colossal eruptionsEven more extreme eruptions have occurred in Earth's past--eruptions ten times more powerful than the Tambora eruption, earning a ranking of 8 out of 8 on the Volcanic Explosivity Index (VEI). These "mega-colossal" eruptions occur only about once every 10,000 years, but have much longer-lasting climatic effects and thus are a more significant threat to human civilization. According to the Toba Catastrophe Theory, a mega-colossal eruption at Toba Caldera, Sumatra, about 74,000 years ago, was 3500 times greater than the Tambora eruption. According to model simulations, an eruption this large can pump so much sulfur dioxide gas into the stratosphere that the atmosphere does not have the capacity to oxidize all the SO2 to sulfuric acid aerosol. The atmosphere oxidizes as much SO2 as it can, leaving a huge reservoir of SO2 in the stratosphere. This SO2 gradually reacts to form sulfuric acid as the OH radicals needed for this reaction are gradually produced. The result is a much longer-lasting climate effect than the 1 - 2 years that the magnitude 6 and 7 events of 535, 1600, 1815, and 1991 lasted. A magnitude 8 eruption like the Toba event can cool the globe for 6 - 10 years (Figure 3), which may be long enough to trigger an ice age--if the climate is already on the verge of tipping into an ice age. Rampino and Self (1992) argued that the sulfur aerosol veil from Toba was thick and long-lasting enough to cool the globe by 3 - 5°C (5 - 9°F), pushing the climate--which was already cooling and perhaps headed towards an ice age--into a full-scale ice age. They suggested that the response of Canada to the volcano played a particularly important role, with their model predicting a 12°C (22°F) reduction in summer temperatures in Canada. This would have favored the growth of the Laurentide ice sheet, increasing the reflectivity (albedo) of the Earth, reflecting more sunlight and reducing temperatures further. The controversial Toba Catastrophe Theory asserts that the resulting sudden climate change reduced the Earth's population of humans to 1,000 - 10,000 breeding pairs. More recent research has shed considerable doubt on the idea that the Toba eruption pushed the climate into an ice age, though. Oppenheimer (2002) found evidence supporting only a 2°F (1.1°C) cooling of the globe, for the 1000 years after the Toba eruption. Zielinski et al. (1996) argued that the Toba eruption did not trigger a major ice age--the eruption merely pushed the globe into a cool period that lasted 200 years. Interestingly, a previous super-eruption of Toba, 788,000 years ago, coincided with a transition from an ice age to a warm period.

Figure 2. The 100x30 square kilometer Toba Caldera is situated in north-central Sumatra around 200 km north of the Equator. It is comprised of four overlapping calderas aligned with the Sumatran volcanic chain. Repeated volcanic cataclysms culminated in the stupendous expulsion of the Younger Toba Tuff around 74,000 years ago. The lake area is 100 square kilometers. Samosir Island formed as a result of subsequent uplift above the evacuated magma reservoir. Such resurgent domes are typically seen as the concluding phase of a large eruption. Landsat Enhanced Thematic Mapper Plus (ETM+) browse images for path/row 128/58 (6 September 1999) and 129/58 (21 January 2001) from http://landsat7.usgs.gov/. Copyright USGS. Image source: Oppenheimer, C., 2002, "Limited global change due to the largest known Quaternary eruption, Toba 74 kyr BP?"Quaternary Science Reviews, 21, Issues 14-15, August 2002, Pages 1593-1609.

Figure 3. Total mass of sulfur dioxide and sulfate aerosol in the stratosphere (heavy solid and dotted lines, respectively) modeled for a 6 petagram stratospheric injection of SO2. Observed SO2 and aerosol mass for the 1991 Pinatubo eruption are shown for comparison. The much larger amount of SO2 in the Toba simulation soaks up all available oxidants in the stratosphere leading to a much longer lifetime of SO2 and, in turn, prolonging the manufacture of sulfate aerosol. Data from Read et al. (1993) and Bekki et al. (1996). Image source: Oppenheimer, C., 2002, "Limited global change due to the largest known Quaternary eruption, Toba 74 kyr BP?"Quaternary Science Reviews, 21, Issues 14-15, August 2002, Pages 1593-1609.

When can we expect the next mega-colossal eruption?Given the observed frequency of one mega-colossal magnitude 8 volcanic eruption every 1.4 million years, the odds of another hitting in the next 100 years is about .014%, according to Mason et al., 2004. This works out to a 1% chance over the next 7200 years. Rampino (2002) puts the average frequency of such eruptions at once every 50,000 years--about double the frequency with which 1-km diameter comets or asteroids capable of causing a similar climatic effect hit the Earth. A likely location for the next mega-colossal eruption would be at the Yellowstone Caldera in Wyoming, which has had magnitude 7 or 8 eruptions as often as every 650,000 years. The last mega-colossal eruption there was about 640,000 years ago. But don't worry, the seismic activity under Yellowstone Lake earlier this year has died down, and the uplift of the ground over the Yellowstone caldera that was as large as 7 cm/yr (2.7 inches/yr) between 2004 - 2006 has now fallen to 4 cm/yr, according to the Yellowstone Volcano Observatory. The USGS states that "the Yellowstone volcanic system shows no signs that it is headed toward such an eruption. The probability of a large caldera-forming eruption within the next few thousand years is exceedingly low".

What would happen if a magnitude 8 mega-colossal eruption were to occur today?If a mega-colossal eruption were to occur today, it would probably not be able to push Earth into an ice age, according to a modeling study done by Jones et al. (2005). They found that an eruption like Toba would cool the Earth by about 17°F (9.4°C) after the first year (Figure 3), and the temperature would gradually recover to 3°F (1.8°C) below normal ten years after the eruption. They found that the eruption would reduce rainfall by 50% globally for the first two years, and up to 90% over the Amazon, Southeast Asia, and central Africa. This would obviously be very bad for human civilization, with the cold and lack of sunshine causing widespread crop failures and starvation of millions of people. Furthermore, the eruption would lead to a partial loss of Earth's protective ozone layer, allowing highly damaging levels of ultraviolet light to penetrate to the surface.

Not even a mega-colossal eruption of this magnitude would stop global warming, though. The level of greenhouse gases in the atmosphere would not be affected by the volcanic eruption, and warming would resume where it left off once the stratospheric dust settled out in a decade. With civilization crippled by the disaster, greenhouse gas emissions would be substantially reduced, though (small solace!) If we really want to say goodbye to civilization, a repeat of the only magnitude 9 eruption in recorded history should do the trick--the magnitude 9.2 La Garita, Colorado blast of 27.8 million years ago (Mason et al., 2004).

Figure 4. Annual near-surface temperature anomalies for the year following a mega-colossal volcanic eruption like the Toba eruption of 74,000 years ago, if it were to occur today. Most land areas cool by 22°F (12°C) compared to average. Some areas, like Africa, cool by 29°F (16°C). Image credit: Jones, G.S., et al., 2005, "An AOGCM simulation of the climate response to a volcanic super-eruption", Climate Dynamics, 25, Numbers 7-8, pp 725-738, December, 2005.

What would happen if a magnitude 7 super-colossal eruption were to occur today?An eruption today like the magnitude 7 events of 535 A.D. or 1815 would cause cause wide-spread crop failures for 1 - 2 years after the eruption. With food supplies in the world already stretched thin by rising population, decreased water availability, and conversion of cropland to grow biofuels, a major volcanic eruption would probably create widespread famine, threatening the lives of millions of people. Wars over scarce resources might result. However, society's vulnerability to major volcanic eruptions is less than it was, since the globe has warmed significantly in the past 200 years. The famines from the eruptions of 1600 and 1815 both occurred during the Little Ice Age, when global temperatures were about 1.4°F (0.8°C) cooler than today. Crop failures would not be as wide-spread with today's global temperatures, if a suer-colossal eruption were to occur. Fifty years from now, when global temperatures are expected to be at least 1°C warmer, a magnitude 7 eruption should only be able to cool the climate down to year 2009 levels.

Volcanoes also warm the climateWhile volcanoes cool the climate on time scales of 1 - 2 years, they act to warm the climate over longer time scales, since they are an important source of natural CO2 to the atmosphere. Volcanoes add 0.1 - 0.3 gigatons (Gt) of carbon to the atmosphere each year, which is about 1 - 3% of what human carbon emissions to the atmosphere were in 2007, according to the Global Carbon Project. In fact, volcanoes are largely responsible for the natural CO2 in the atmosphere, and helped make life possible on Earth. Why, then, haven't CO2 levels continuously risen over geologic time, turning Earth into a steamy hothouse? In fact, CO2 levels have fallen considerably since the time of the dinosaurs--how can this be? Well, volcano-emitted CO2 is removed from the atmosphere by chemical weathering. This occurs when rain and snow fall on rocks containing silicates. The moisture and silicates react with CO2, pulling it out of the air. The carbon removed from the air is then washed into the sea, where it ends up in ocean sediments that gradually harden into rock. Rates of chemical weathering on Earth have accelerated since the time of the dinosaurs, largely due to the recent uplift of the Himalaya Mountains and Tibetan Plateau. These highlands undergo a tremendous amount of weathering, thanks to their lofty heights and the rains of the Asian Monsoon that they capture. Unfortunately, chemical weathering cannot help us with our current high levels of greenhouse gases, since chemical weathering takes thousands of years to remove significant amounts of CO2 from the atmosphere. It takes about 100,000 years for silicate weathering to remove 63% of the CO2 in the atmosphere. Thus, climate models predict that chemical weathering will solve our greenhouse gas problem in about 100,000 - 200,000 years.

Portlight moves to provide relief for South Carolina wildfiresSouth Carolina's biggest wildfire in more than three decades --a blaze four miles wide--destroyed dozens of homes near Myrtle Beach yesterday. Portlight Strategies, Inc. is preparing to respond to this disaster, focusing on providing drinks and sanitary products to firefighters, particularly to rural volunteer fire departments and other first responders which do not have the same resources as some of the larger paid departments. To help out, visit the Portlight South Carolina fire relief web page. Thanks!

I took a different view of this last night when I found out my boss's 2 year old is in the hospital with severe flu like symoptoms in Ohio. They just left from Tampa 2 days ago. I am hoping for the best.

Quoting Ossqss:Be aware that the rules of engagement are different under the current state of gov. They can lock down an apartment complex or even a community in order to mitigate spread of the illness. That's their job right now. I certainly don't want to eat MRE's if that were to happen. Don't get me wrong, the chances are slim, but are still chances non the less.

Galveston was severely battered last September by Hurricane Ike and there was much criticism about the lack of evacuation procedures on the barrier island. Lyda Ann Thomas, with her distinctive Texas drawl, became familiar to viewers of Houston television coverage of the storm -- including the present writer wondering if Ike would strike his new hometown of Port Lavaca, about 100 miles down the Gulf coast. It didn't get to us, although many people in Port Lavaca evacuated and plywood became the exterior decor of choice for homes and businesses.

Be aware that the rules of engagement are different under the current state of gov. They can lock down an apartment complex or even a community in order to mitigate spread of the illness. That's their job right now. I certainly don't want to eat MRE's if that were to happen. Don't get me wrong, the chances are slim, but are still chances none the less.

Quote from the phase 4 item

Any country that suspects or has verified such an event should urgently consult with WHO so that the situation can be jointly assessed and a decision made by the affected country if implementation of a rapid pandemic containment operation is warranted.

Quoting Ossqss:I would encorage everyone to treat the flu item as if it were a hurricane 7 days out in the cone of uncertainty and build preparation of food stuffs and meds for fever etc. If you are going to build a hurrican kit, why not finish it sooner than later. If this thing hits near your home, you are not going to want to visit the stores with the hundreds of others who will panic at the last minute. Just like they do when a Hurrican is coming. Just my take. Be prepared and avoid being scared.

Plus, stores will run out of the most needed items. Yesterday I bought one of the last bottles of hand sanitizer.

Quoting Ossqss:I would encorage everyone to treat the flu item as if it were a hurricane 7 days out in the cone of uncertainty and build preparation of food stuffs and meds for fever etc. If you are going to build a hurrican kit, why not finish it sooner than later. If this thing hits near your home, you are not going to want to visit the stores with the hundreds of others who will panic at the last minute. Just like they do when a Hurrican is coming. Just my take. Be prepared and avoid being scared.

I would encorage everyone to treat the flu item as if it were a hurricane 7 days out in the cone of uncertainty and build preparation of food stuffs and meds for fever etc. If you are going to build a hurrican kit, why not finish it sooner than later. If this thing hits near your home, you are not going to want to visit the stores with the hundreds of others who will panic at the last minute. Just like they do when a Hurrican is coming. Just my take. Be prepared and avoid being scared.

Quoting melwerle:Just kind of a rambling thought on the flu...several cases in San Diego county (hubby is there right now working) and I was thinking - alot of these folks come across the border every day for work and school...I think with what is already there with the flu, we are going to see ALOT more coming up in the next week or so. Kids in school (little ones and teenagers as well) don't get it when you tell them to cover the mouth when they cough or wash their hands whenever they touch something (doorknobs, desks, handing papers back to each other from desk to desk when the teacher passes something out). How many things do you "touch" each day...how many opportunities do you have to wash your hands throughout the day when you're a student? How many times do you touch your face or pop gum or candy into your mouth?

I don't believe in panic but I do believe in prevention.

This is why I went out and bought hand sanitizer. They make small bottles of it now that fit easily into a pocket.

Quoting TampaSpin:Some poeple like to post funny pics and post funny things not really understanding the true impact of the threat of the Swine Virus. There are 36000 deaths that occur annually from the common Flu. If 4 times than normal become sick from the Swine than in a normal year then at least 120,000 plus deaths will occur. Keeping in mind that the common Flu will still kill 36,000 also. So now we are over 150,000 deaths just in the US from the Flu Virus of all kinds. I'm not trying to hype the seriousness of this but, being within close touch with the Medical Field I do get a sense of the complete impact that could be felt. I'm sure to receieve cracked emails and post that i am scaring people for no reason. But, if this thing spreads as expected then reality hit. Keep in mind, the elderly and the very young will be a highest risk which the Swine has not hit yet because they was not the travelers. There is a 7-10 incubation period, so by next late next week we will have a more sense as to just how quickly this is spreading and the total impact. Just a thought, do you think the Government wants people out of work and creating anything negative with such a fragile economy. Could they be underplaying this also?

Just kind of a rambling thought on the flu...several cases in San Diego county (hubby is there right now working) and I was thinking - alot of these folks come across the border every day for work and school...I think with what is already there with the flu, we are going to see ALOT more coming up in the next week or so. Kids in school (little ones and teenagers as well) don't get it when you tell them to cover the mouth when they cough or wash their hands whenever they touch something (doorknobs, desks, handing papers back to each other from desk to desk when the teacher passes something out). How many things do you "touch" each day...how many opportunities do you have to wash your hands throughout the day when you're a student? How many times do you touch your face or pop gum or candy into your mouth?

Some poeple like to post funny pics and post funny things not really understanding the true impact of the threat of the Swine Virus. There are 36000 deaths that occur annually from the common Flu. If 4 times than normal become sick from the Swine than in a normal year then at least 120,000 plus deaths will occur. Keeping in mind that the common Flu will still kill 36,000 also. So now we are over 150,000 deaths just in the US from the Flu Virus of all kinds. I'm not trying to hype the seriousness of this but, being within close touch with the Medical Field I do get a sense of the complete impact that could be felt. I'm sure to receieve cracked emails and post that i am scaring people for no reason. But, if this thing spreads as expected then reality hit. Keep in mind, the elderly and the very young will be a highest risk which the Swine has not hit yet because they was not the travelers. There is a 18 to 72 hour incubation period but, it takes 7-10 days to see it spread, so by next late next week we will have a more sense as to just how quickly this is spreading and the total impact. Just a thought, do you think the Government wants people out of work and creating anything negative with such a fragile economy. Could they be underplaying this also?

Wow.. Not unusual to have a 20 degree difference between low at night and high during the day (if the sky is clear)in Charleston. But 25-30 degree difference without a front moving through! That is something else. Y'all have had some significant weather this spring.

If I understand the mechanism by which this respiratory flu spreads, it is by infected particulate matter that has been expectorated/coughed by the infected person. That stuff is too heavy to stay in the air long, so you would have to inhale it while the person is coughing, or physically transfer it to your respiratory tract (Hence the importance of cough hygiene, washing hands and not touching eye, nose, mouth).

If this is not accurate, I trust someone in the medical community will correct my errors.

Quoting JFLORIDA:It is a novel mixture of strains that seems to be spreading with ease (possibly even unimpeded) to younger age groups.

I have not seen a reference to which anything occurring before 1960 would lend resistance.

But its severalty might be reduced by later encountered strains.

Indeed. Young children do not have the self-discipline to exercise the discipline of hand washing, cough hygiene, and not touching their eyes, nose and mouth without washing hands.If I had a young one in daycare or school, I would be concerned.

The 6Z GFS continues to forecast tropical development in the SW Caribbean but I'm not 100% sure the development may take place in he Caribbean. However, with wind shear forecast to be between 10-20 knots, marginal SSTs and ample moisture and lift along with anomalously low pressure the area will become a breeding ground for anything that tries to develop. The monsoon trough is a notorious feature in tropical cyclogeneisis in the Eastern Pacific and occasional (as in this case) it extends across Central America in the SW Caribbean, typically in May, June and October. The area lacks model supports except for some models which show high rainfall surrounded by broad low pressure. It has been consistent with development but inconsistent in track. The factors that support the GFS outweighs the factors that don't.

Quoting stoormfury:morningalthough the gfs is still showing cyclogenesis in the southwest caribbean, the odds are being stacked against this possibility. there is little vorticity in the area as well as high noeth easterly wind shear of about 50-60 knots. any system which tries to form in this area will be completly destroyed. i suspect we will have to wait for the middle of may for something to happen

morningalthough the gfs is still showing cyclogenesis in the southwest caribbean, the odds are being stacked against this possibility. there is little vorticity in the area as well as high noeth easterly wind shear of about 50-60 knots. any system which tries to form in this area will be completly destroyed. i suspect we will have to wait for the middle of may for something to happen

Moisture is beginning to make its way into the Caribbean. However, as Taz pointed out, shear levels are still substantially prohibitive, as high as 50 knots in some areas of the southwest Caribbean, where our potential tropical cyclone could develop in the coming days.

Shear does seem to be gradually decreasing in the region, however, but it is still nowhere near favorable levels.

Tropical Disturbance Summary (0600z 29APR)==============================================An area of convection (96W) located at 14.4N 117.3E or 215 NM west of Manila, Philippines. Recent animated multispectral satellite imagery shows an elongated low level circulation center with deep convection near the center and broken convective banding wrapping into the southern periphery. A 2423z TRMM pass shows deep convective banding curving into the eastern flank of the system with broken convecting banding to the south. Upper level analysis shows the system is in an area of low vertical wind shear and located under the upper level ridge axis. Animated water vapor imagery shows good equatorward outflow and poleward outflow appears to be suppressed by surface ridging to the north.

Maximum sustained winds near the center is 15-20 knots with a minimum sea level pressure of 1007 MB. The potential for this disturbance to form into a significant tropical cyclone within the next 24 hours is FAIR.

---Philippines or Vietnam needs to stay on alert it is getting active in the southwestern part of the West Pacific.

Quoting quasigeostropic:Computer models go through transitional periods between winter/summer(spring) and from summer to winter(fall). The equations in the computer models used for winter forecasting are different than the equations used for the summer regime. The result of such transitional periods are that models will spin up many false systems as they transition to a summer regime for example.

Computer models go through transitional periods between winter/summer(spring) and from summer to winter(fall). The equations in the computer models used for winter forecasting are different than the equations used for the summer regime. The result of such transitional periods are that models will spin up many false systems as they transition to a summer regime for example.